IPIDCONTROLLER (proportional-integral-derivative controller)

Configure and control the inputs and outputs used for proportional-integral-derivative (PID) logic. PID logic is used to control physical properties such as temperature, pressure, liquid, level, or flow rate by using process loops that calculate an error value as the difference between a desired setpoint and a measured process variable. The controller attempts to minimize the error over time by the adjustment of a control variable. The calculation includes proportional (P), integral (I), and derivative(D) terms, which are used as follows:
  • P: Present values of the error.
  • I: Past values of the error.
  • D: Possible future values of the error, based on its current rate of change. which controls physical properties such as temperature, pressure, liquid level, or flow rate using process loops.
Languages supported: Function block diagram, ladder diagram, structured text.
This instruction applies to the Micro810, L20E, L50E, and L70E controllers.
IPIDCONTROLLER
IPIDCONTROLLER
IPIDCONTROLLER parameters
Parameter
Parameter Type
Data Type
Description
EN
Input
BOOL
When TRUE, enables the instruction block.
  • TRUE: Execute the PID calculation.
  • FALSE: The instruction block is idle.
Applies to ladder diagram programs.
Process
Input
REAL
Process value, which is the value measured from the process output.
SetPoint
Input
REAL
Set point.
FeedBack
Input
REAL
Feedback signal, which is the value of the control variable applied to the process.
For example, the feedback can be IPIDCONTROLLER output.
Auto
Input
BOOL
The operation mode of the PID controller:
  • TRUE: Controller runs in normal mode.
  • FALSE: Controller causes reset R to track (F-GE).
Initialize
Input
BOOL
A change in value (TRUE to FALSE or FALSE to TRUE) causes the controller to eliminate any proportional gain during that cycle. Also initializes AutoTune sequences.
Gains
Input
GAIN_PID
Gains PID for IPIDController.
Use the GAIN_PID data type to define the parameters for the Gains input.
AutoTune
Input
BOOL
  • TRUE: When AutoTune is TRUE and Auto and Initialize are FALSE, the AutoTune sequence is started.
  • FALSE: Do not not start Autotune.
ATParameters
Input
AT_Param
Auto Tune Parameters.
Use the AT_Param data type to define the parameters for the ATParameters input.
Output
Output
REAL
Output value from the controller.
AbsoluteError
Output
REAL
Absolute error (Process – SetPoint) from the controller.
ATWarnings
Output
DINT
(ATWarning) Warning for the Auto Tune sequence. Possible values are:
  • 0: No auto tune done.
  • 1: In auto tune mode.
  • 2: Auto tune done.
  • -1: ERROR 1 input automatically set to TRUE, no auto tune possible.
  • -2: ERROR 2 auto tune error, ATDynaSet expired.
OutGains
Output
GAIN_PID
Gains calculated after AutoTune sequences.
Use the GAIN_PID data type to define the OutGains output.
ENO
Output
BOOL
Enable output.
Applies to ladder diagram programs.

IPIDCONTROLLER examples

IPIDCONTROLLER function block diagram example
IPIDCONTROLLER function block diagram example
IPIDCONTROLLER ladder diagram example
IPIDCONTROLLER ladder diagram example
IPIDCONTROLLER structured text example
(* ST equivalence: IPIDController1 is an instance of IPIDController block *)


IPIDController1(Proc,

SP,
FBK,
Auto,
Init,
G_In,
A_Tune,
A_TunePar,
Err );
Out_process := IPIDController1.Output ;

A_Tune_Warn := IPIDController1.ATWarning ;

Gain_Out := IPIDController1.OutGains ;
Results
Results
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